There have only few 6-level papertape codesbeen used, I know of three.
All are based on the 5-level CCITT #2
code. The last two were used in Teletypesetting.
The following codes are given:
CCITT #4
This code follows the previous 7-level CCITT
#3 and is followed by the 8-level CCITT
#5. It is based on CCITT #2 and does
not add much to it, only three control symbols. Like the original the
undefined entries in the lower part are for national use, it was not the
intention that the undefined entries in the upper part would be used.
TTS
TTS systems for Teletypesetting have distinguishing cases. The first
is lower case vs. upper case, the second is lower rail vs. upper rail.
The lower rail codes for TTS systems is the same for the two basic
systems I know of (there can be individual differences of course), and
is shown above. The upper rail part accomodates italics and small
capitals. The assignment of italics is trivial, the assignment of
small capitals is not so easy. Because of mechanical constraints a
small cap symbol should be paired with a lower rail symbol of the same
width. This lead to considerable differences in the assignments in the
US and in Great Britain. The upper rail assignments are shown next:
British TTS
The British upper rail part. Some lower rail symbols show also here in
upper rail, that is because in those cases there is no separate upper
rail feed. Missing are the italic lower case x and the small capital X.
US TTS
And here the US upper rail part. The notes given with the British part
also apply here. Missing in the US version are the italic upper case Z
and the small capitals X and Z.